"Gravitropism" means growth in response to gravity [1]. I use the term gravitropism in art beyond its biological origin, to underscore the fact that gravity plays a fundamental role in the forms and events we are able to create on Earth, and that forms and events created in zero gravity to be experienced in the same environment might be radically different. Gravity is the weakest known force, but is the most evident in our everyday life. While great minds have tried to understand it, from Galileo and Newton to Einstein and Hawking, it still remains fundamentally unclear. And while its reconciliationt with quantum mechanics is a remit of modern and contemporary physics, it has been largely marginal in modern and contemporary art. I first wrote about gravitropic forms and events in 1987, while creating and articulating the theory of a new poetic language produced out of light, with protean linguistic events floating and changing in space, freed from material and gravitational constraints. In my original text I stated: "As we experience massless optical volumes -- focused luminous vibrations suspended in the air -- "gravitropism" (form conditioned by gravity) makes way for "antigravitropism" (creation of new forms not conditioned by gravity), freeing the mind from the clichés of the physical world and challenging the imagination". [2] I coined the word "antigravitropism" to retain the affirmative quality of negating or neutralizing gravity.

The powerful gesture of defying gravity in art can be traced back to innovative early twentieth-century sculptors, such as Calder and Moholy-Nagy. While the first reduced the support of massive structures to a single suspended point with his "Mobiles", the second went as far as experimenting directly with levitation, with absolutely no physical support whatsoever. In his seminal book "Vision in Motion", published posthumously in 1947, Moholy-Nagy appears levitating a chisel with compressed air. The photograph is striking: we see Moholy-Nagy's profile and before him the object suspended in the air with no apparent means of support. In previous books Moholy-Nagy articulated notions about the evolution of sculptural form, suggesting that the virtual volume--volume created optically by the accelerated motion of an object--was a new possibility for sculpture. In his film "Design Workshops" (1946), he presented a sequence, less than a minute long, in which colored ping pong balls float in an air jet. As an artist crossing many discipline boundaries, Moholy-Nagy also considered that in the future the neutralization of gravity could be a useful tool in design. It was not until the 1960s that several of this visionary's ideas would find currency. Hans Haacke's sculpture "Sphere in Oblique Air-Jet" (1967), presents the viewer with precisely what its title indicates: a buoyant balloon that stably hovers in space. The sculpture accomplishes this feat through what is known as Bernoulli's principle, according to which a stream of air (or fluid) has lower pressure than stationary air (or fluid). On a practical level, this means that moving air can create aerodynamic lift.

Although the Hungarian constructivist did not explore this notion in his own sculptures, levitation and the conquest of space attracted the attention of artists working in the 1950s. Lucio Fontana's Spatialist movement, for example, made direct references to space. In 1951 he clearly stated: "Man's real conquest of space is his detachment from the earth". Aaron Siskind's 1950s series of photographs "Terrors and Pleasures of Levitation" present the viewer with contorted and airborne human bodies. These compelling images, which evoke humankind's mythical dream of flying, look as though they could be right out of an astronaut training program. While in both cases it is really the metaphor of space and levitation that is brought to the fore, the use of magnetism to suspend forms in space became the key element in the innovative work of the Greek kinetic artist Takis. In 1938 Gyorgy Kepes produced a series of photographs and photograms in which he experimented with the visual properties of magnets and iron filings, but it was Takis who, in 1959, introduced the aesthetic of sculptural magnetic levitation with his elegant "Télésculpture". The sculpture is composed of three small conical metal pieces that are attached, through thin wires, to three nails. The three conical pieces are suspended above an irregular plane and levitate in front of a magnet. This was the seed of a complex body of work through which this magician of levitation has investigated the expressive power of invisible forces. In September of 1959, the Moon was first visited by the Soviet spacecraft Lunik 2. As the first probe to impact the Moon, Lunik 2 made evident that human displacement in space was on the horizon. Fascinated by the implications of this idea, Takis realized an event in 1960 at the Iris Clert Gallery, in Paris, entitled "L'Impossible, Un Homme Dans L'Espace" (The Impossible, A Man in Space). Donning a "Space Suit" designed by Takis, wearing a helmet, and attached to a metal rod connected to the floor, Sinclair Belles was "launched" across the gallery onto a safety net. The event orchestrated by Takis pointed to the unknown: the logic and the biologic that govern human existence on Earth will not readily apply to our life in space. Also responding to the visual and intellectual stimulation provided by humankind's first steps beyond the Earth, Yves Klein's "Leap into the Void" (1960) was a photomontage alluding to the new condition of the body considered, rather concretely, in relation to the cosmos (reminiscent as it was of Siskind's series). It is worth noting that other artists active in the 1960s further elaborated the vocabulary of magnetism. Harvard-educated Venezuelan sculptor Alberto Collie created electromagnetic levitators for innovative sculptures called spatial absolutes. In his sculptures he employed titanium disks that float freely (that is, with no point of attachment) in an electromagnetic field. If the disk budges, a feedback system strengthens the field, thus keeping the disk in its state of equilibrium.

Partially inspired by the incipient space program, the utopian architecture of the 1960s yielded visions of floating communities hovering among the clouds. Buckminster Fuller and Shoji Sadao created such a concept, entitled "Project for Floating Cloud Structures (Cloud Nine)." Fuller's imaginary floating sphere-enclosed cities are given a sense of feasibility through technical explanations that would seem to render them possible. The visionary architect drafted plans in the early sixties for spheres that would hover above the earth and hold several thousand "passengers."

One peculiar approach to the suspension of (ephemeral) forms in space is the use of vaporous substances through a technique known as Skywriting, which consists in the writing or drawing formed in the sky by smoke or another gaseous element released from an airplane, usually at approximately 10,000 feet. In the late 1960s and early seventies, artists such as James Turrel, Sam Francis, and Marinus Boezem started to employ skywriting as a medium. Poet David Antin created skypoems over Los Angeles and San Diego in1987-1988. These and other artists and writers created evanescent forms within what is known as troposphere, that is, the lowest atmospheric layer. Pushing the concept of a sky art into the space age, beyond aerial acrobatics and the design of evanescent forms, the Brazilian artist Paulo Bruscky proposed, in 1974, the creation of an artificial aurora borealis, which according to the artist would be produced by airplanes coloring cloud formations. Bruscky published ads in newspapers to both document the project and inform the public. The ads were also an instrument in his search for sponsors. They were published in the Brazilian papers Diário de Pernambuco, in Recife, September 22, 1974 and Jornal do Brasil, Rio de Janeiro, December 29, 1976. While on a Guggenheim fellowship in New York, he also published ads in the Village Voice, New York, May 25, 1982. The creation of artificial auroras was realized in 1992, not by Bruscky, but by NASA as part of environmental research. Approximately sixty artificial mini-auroras were created by employing electron guns to fire rays at the atmosphere from the space shuttle Atlantis. The sky was also the environment of "Searchlight", an artwork created by Forrest Myers in 1975. Myers used four carbon-arc searchlights and made them converge to a point above Artpark, Lewiston, New York. This light sculpture created the form of a pyramid, oscillating between the material reality of an ephemeral urban intervention and the image of an immemorial monument.

Paulo Bruscky, "Space Art" proposal, published in Jornal do Brasil, Rio de Janeiro, December 29, 1976. (Click on image to see full page)

Forrest Myers, "Searchlight", 1975.

David Antin, "Skypoems", 1987-1988

Vik Muniz's contribution to "En el Cielo", 2001

The artistic use of skywriting further extended the aerial performances set forth in Futurist manifestoes. In addition to the well-known writings of Futurism's founder, Filippo Tommaso Marinetti, of particular relevance is the 1919 manifesto "Futurist Aerial Theatre", by Fedele Azari, in which he wrote: "I HAVE MYSELF PERFORMED, IN 1918, MANY EXPRESSIVE FLIGHTS AND EXAMPLES OF ELEMENTARY AERIAL THEATRE OVER THE CAMP OF BUSTO ARSIZIO. I perceived that it was easy for the spectators to follow all the nuances of the aviator's states of mind, given the absolute identification between the pilot and his airplane, which becomes like an extension of his body: his bones, tendons, muscles, and nerves extend into longerons and metallic wires." Futurist interest for airplanes and aerial performance where largely explored through representational means, most successfully in the works or aeropainter Tullio Crali, whose first actual flight, on a seaplane, took place in 1928. His 1939 canvas "Incuneandosi nell'abitato (In tuffo sulla città)" [Nose Dive on the City] indeed shows a small airplane nosediving towards a nondescript city of skyscrapers as seen from the cockpit. We see the back of the pilot's head but there's no gap separating us from the pilot. The painting does not suggest that the viewer is a passanger. The compressed space aims at vicariously placing the viewer in the position of the pilot and evoking the enthusiasm for aggression and power that characterized Futurism. Rendered in dizzying
perspective, the painting has steep angles and dissolving forms, suggesting that at accelerating speed the plane will soon hit the ground (or the buildings). "Incuneandosi nell'abitato" is Crali's most accomplished work and the most emblematic of Futurist aeropaintings. In response to the space race and the moon landing, in 1969 Crali printed and distributed his "Arte Orbitale: Manifesto futurista" [Orbital Art, A Futurist Manifesto]. Alone intriguing for retaining the "Futurist" epithet well into the late 1960s, the manifesto moves Crali's ideas beyond the pictorial realm and proposes plans for artworks that "created in collaboration with scientists and technicians will be placed in orbit around the earth". The manifesto even aludes to the use of "the most advanced techniques" to create "luminous plastic spectacles" competing with "comets aurora borealis rainbows galaxies supernovae" [sic].

Another significant, albeit little known antecedent, is the "Dimensionist Manifesto", published in 1936 by the Hungarian poet Károly (aka Charles) Sirato and signed by Arp, Delaunay, Duchamp, Kandinsky, Moholy-Nagy, and Picabia, among others. The "Dimensionist Manifesto" was published in Paris as a loose sheet attached to the magazine Revue N + 1. Its most ambitious proposal is four-dimensional sculpture: "Ensuite doit venir la creation d'un art absolument nouveau: l'art cosmique (Vaporisation de Ia sculpture, theatre Syno-Sens - denominations provisoires). La conquête totale de l'art de l'espace à quatre dimensions (un "Vacuum Artis" jusqu'ici). La matière rigide est abolie et remplacée par des matériaux gazéfiés. L'homme au lieu de regarder les objets d'art, devient lui-même le centre et le sujet de la création, et la création consiste en des effets sensoriels dirigés dans un espace cosmique fermé." This anticipatory vision would become a reality decades later in multiple ways. One such form was the use of vapors and gases as new art materials, from Robert Barry's "Inert Gas Series: Neon" (1969), in which he documents, with two black-and-white 8-by-10 photographs and a typewritten text, the release of a small amount of neon gas into the landscape around L.A., to the sublime "solid light installations" by Anthony McCall, the first of which ("Line Describing a Cone") dates from 1973. In a room gently filled with mist by a smoke machine, a light beam projects a single bright dot that, in the course of 30 minutes, extends itself into a line that slowly forms the outer skin of a hollow cone.

In 1998 Javier Perez created "Smoke Man", a sculpture in which a headless male figure gives off periodic puffs of smoke and in 2002 Pierre Huyghe produced "L'Expédition Scintillante, Act II: Untitled (light show)", in which multiple gases are lit by filtered lights producing a spectacle of evanescent colored forms to the rythm of music. Another way that gases have been used in art is through skywriting, as exemplified by "En el Cielo", an exhibition of skywriting projects created by several artists for the Venice Biennial in 2001 and organized by TRANS>, a New York organization that presents experimental art. In spite of its appeal to artists, though, skywriting is itself a vanishing art form, having been largely replaced in the commercial world by a faster skymessaging technique, known as "skytyping", in which several planes fly in formation and use a computer-controlled radio signal to emit puffs of smoke that form letters. By 2010, be it with laser projection or computer-controlled smoke emmissions, it could be said that gases had become a regular contemporary art medium, as exemplified by works such as "Memory Cloud" (2008) by Minimaforms , "Trinity Model" (2010) by János Borsos, "For Those Who See" (2010) by Daniel Schulze, and "Pippen over Ewing" (2010) by Mitchell Chan.

Bruscky's proposal explored a scale greater than the Land Art or the Earthworks typical of the period, since his vision of an artificial aurora borealis would reach millions at once, who would see the work simply by looking up at the sky. By contrast, works that manipulate magnetism or electromagnetism often have a smaller, more intimate scale. If Takis' work has a forceful and raw power that emanates from his unadorned handling of materials such as iron and steel, quite different are the levitation projects by the American artist Thomas Shannon. Shannon has been creating since the early 1980s a series of sculptures based on materials such as bronze, gold, and marble, as well as painted wood, in which the source of magnetism is not visible. Rather than seeking to make evident the tension that results when opposite poles attract, Shannon's sculptures search for a sense of quiet equilibrium, resting on the visual harmony created by the presence of two basic components: the base and the floating element. Finding in science and natural phenomena a rich source for visual research, Shannon's vocabulary takes levitation into the realm of a reduced articulation of sculptural forms where pairing of objects structures the magnetic experience.

Many developments in twentieth-century art led to a radical reduction in the use of physical matter to form sculptural volume and to support or present this volume in space. From Gabo's constructions (1919/20) to Fontana's perforations, from Moholy-Nagy kinetic works to Calder's mobiles, we have witnessed a movement to liberate modern sculpture from the constraints of enclosed and static form resting on the two-dimensional surface of the pedestal. Artists such as Takis and Shannon -- and the Brazilian sculptor Mario Ramiro, who in 1986 created a self-regulating electromagnetic levitator entitled G0 (standing for "zero gravity") -- have given continuation to this search to release sculpture from gravitropism. In Ramiro's "Gravidade Zero" (Zero Gravity), an electromagnet regulated by a photo-sensor maintains a metallic form floating in space in a state of levitation. Freed from a two-dimensional base, and from any point of support in space, this object is in a truly three-dimensional kinetic space. Ramiro's levitating form presents volume-inversion relations: The area of the object's greater mass can be seen at the top. The lower part, the traditional base of the object, does not need to support the volume above it.

The inevitable conclusion is that zero gravity is the next frontier. Artworks have been taken aboard spacecrafts since 1969, when "The Moon Museum", a small ceramic tile with drawings by artists such as Robert Rauschenberg and Andy Warhol, was carried to the Moon aboard a Saturn V rocket on Apollo 12. A significant development was the permanent installation of a sculpture by artist Paul van Hoeydonck (Antwerp, b. 1925) on the surface of the Moon in 1971, also carried on a Saturn V rocket on Apollo 15. Entitled "Fallen Astronaut" (aluminum, 8.5 cm long), the work was placed at the Hadley-Apennine landing site by American astronauts Dave Scott and Jim Irwin (Apollo 15). Next to the sculpture, inserted in the lunar soil is a commemorative plaque, homage to astronauts and cosmonauts who lost their lives in the course of space exploration. In 1989 Lowry Burgess flew objects on the Shuttle as part of a conceptual artwork entitled "Boundless Cubic Lunar Aperture". These works are significant steps towards an art that engages outer space materially, but they were not created in outer space or conceived specifically to investigate the new possibilities of art in true weightlessness. The first works to do so are the sculpture "S.P.A.C.E.", created outside the Earth by American artist Joseph McShane in 1984 and the sculpture "The Cosmic Dancer", created in 1993 by Arthur Woods, an American artist living in Switzerland.

Plate measures 3/4" x 1/2" x 1/40". The drawings are by Myers, Rauschenberg, Oldenburg, Warhol, David Novros, and John Chamberlain.

McShane's work was launched into space on October 5, 1984 aboard the U.S. Space Shuttle Challenger. McShanes piece was produced with the vacuum of space and the conditions of zero gravity and returned to Earth in its altered state. A sphere with a valve and earth atmosphere within was opened once in orbit. The vacuum of space evacuated the sphere, the valve was closed, and the vacuum of space was then contained within. For McShane, the artwork is not the glass object per se, but the containment of outer space within, the potential wonder generated by bringing space vacuum to Earth and to close proximity to viewers. The question concerning the reception of space art necessarily involves a reflection on the experience of it in space. The primary viewers for "The Cosmic Dancer" lived with the "terrors and pleasures of levitation" in conditions of zero gravity. A sharp-angled form launched to the Mir Space Station on May 22, 1993, "The Cosmic Dancer" stressed the cultural dimension of space since it created the experience of art integrated into a human environment beyond Earth. The video that documents the project shows the two Russian cosmonauts Alexander Polischuk and Gennadi Mannakov performing (rotating, hovering, flying) with the sculpture in the confines of Mir, where the sculpture was left. The flaming remnants of the Mir space station plunged into the South Pacific on March 23, 2002.

The Cosmic Dancer sculpture on the mir space station. Space art project by Arthur Woods launched on may 22, 1993.

In the case of Arthur Woods, the performance of the cosmonauts complements his project. As one watches the video documentation, one feels that the cosmonauts stand vicariously for all viewers, that is, all those who in the future will have the opportunity to experience space as a social and cultural milieu, and not only as a research lab. Clearly, the performance of the body in an environment devoid of the forces of gravity is aesthetically rich in its own right. This very issue has been the focus of French choreographer Kitsou Dubois's work for over a decade. Since 1991 she has been flying in microgravity parabolic flights and exploring the gestural, kinesthetic and proprioceptive potential of weightless dance. She has flown alone as well as with other dancers. Dubois is unique in her relentless investigation of zero gravity. In addition to continuously pursuing new levitation opportunities, she has published extensively on the subject, obtained a Ph.D. with her research as the topic of the dissertation, and recreated her experiences in theatrical as well as installation works. As a byproduct of her choreographic work, Dubois has also developed a training method for astronauts based on her new protocols for zero gravity dance.

The spectrum of the live arts in space would be incomplete without theater. In 1999 Slovenian director Dragan Zivadinov staged his Noordung Zero Gravity Biomechanical Theater high above the Moscow skies, onboard a cosmonaut training aircraft. The flight crew consisted of fourteen people: six actors and an audience of eight. A series of eleven airborne parabolas, with gravity changes oscillating from normal, to twice the usual, to 30-second microgravity episodes, is not the most conducive temporal structure for a long dramatic play. This posed no problem for director Zivadinov, whose vision of an abstract theater is well matched by the experience of weightlessness. Zivadinov placed a red set on the back of the plane and seats for the audience of eight on each wall of the aircraft. Launched from the stage into the empty space before it, actors wearing brightly colored costumes performed in a state of levitation, before being pushed down to the floor by gravity changes, and back up in the air again, and so on, as the airplane completed its parabolas. After eight parabolas, Zivadinov allowed the audience to leave their seats and participate in the euphoric state of bodily suspension, a unique form of audience-actor empathy and, undoubtedly, a new level for the old-age dramaturgical device once described by Aristotle as catharsis.

While Zivadinov conceived of the aircraft as a theatrical set, and Woods employed a space station as an ancillary element in the fulfillment of the antigravitropic potential of his sculpture, the media artist, architect, and designer Doug Michaels proposed in 1987 the design of a rather unique space station cum artwork cum "alternative architecture". A co-founder of Ant Farm design group ('68-'78), Michaels was the co-creator of emblematic works of the period, such as Cadillac Ranch (ten cars planted nose down in 1974 in a wheat field located west of Amarillo, Texas) and Media Burn (a 1975 performance in which Michels drove a Cadillac through a pyramid of television sets on fire). In 1986 he established the Doug Michels Studio to pursue innovative projects in architecture and design. Michaels, who passed away in 2003, developed with his colleagues in 1987 a concept for a spacecraft to host artists and scientists interested in human-dolphins interaction and communication. The project resonated with the pioneering work of John Lilly, a scientist who defended the idea that dolphins have consciousness and intelligence at a time when this fact was not yet scientifically established. As a result of his research, Lilly went on to author books such as "Man and dolphin" (Garden City, N.Y., Doubleday, 1961), "The Mind Of The Dolphin: A Nonhuman Intelligence" (Garden City, N.Y., Doubleday, 1967) and "Communication Between Man and Dolphin: The Possibilities of Talking With Other Species" (New York: Crown Publishers, 1978). On its January-February issue of 1987, the magazine The Futurist featured Michaels's Project Bluestar, an orbiting "think tank in zero gravity" meant to include both humans and dolphins. According to the proposed design, the marine mammals' ultrasonic emissions would be used to program the central computer. This proposal was as much about the vision

In 1993, the same year Woods launched "The Cosmic Dancer", the Chinese artist Niu Bo started "The Zero-Gravity Project", which he first pursued in Japan with a plane that flies in parabolic arcs at 20,000-25,000 ft. Bo covered the interior of the plane with rice paper and used a paint produced from the mixture of several elements. To create this paint the artist combined China ink, watercolor, and oil, among other materials, and placed the paint in balloons. During the near weightlessness of microgravity flights, he released the paint. With his "Space Atelier" Bo wishes to convey that just as the Impressionists had to leave their studios to explore the possibilities of natural light, a new culture will be created when artists leave the surface of the Earth.

Niu Bo, The Zero-Gravity Project, 1993.

The Spanish artist and performer Marcel.li Antúnez Roca created Dedalus, a series of microperformances realized in 2003 during two parabolic flights aboard the Tupolev plane, flown at the Gagarin Cosmonaut Training Center, Star City, Russia. This work was part of a larger project carried out by the London organization The Arts Catalyst, which aims to enable artists to work in microgravity conditions. Performing with an exoskeleton wireless interface and the robot Requiem, Roca's involuntary movements activated videos by means of potentiometers in the dresskeletons circuit. The videos explore themes that the artist considers evocative of an exobiological iconography, such as biochemistry/microbiology, higher transgenic organisms and bio robots.

Marcel.li Antúnez Roca, Dedalus, 2003

Artworks such as discussed above open a new realm of speculative inquiry into the future of art in worlds other than the Earth. While we remain confined to the blue planet, three possibilities open up for art that engages what could be called a "zero gravity sensibility". First, it is clear that the potential for magnetism and electromagnetism in art is far from exhausted. Second, the increasing access to microgravity facilities in Russia will force the opening of new markets in Europe, Japan, and the United States, further enabling more artists and performers to explore weightlessness. Third, as plans for space tourism evolve, actual zero gravity might also become more accessible, albeit at a lower pace, since costs will remain high for the foreseeable future. Space tourism was jumpstarted on April 28, 2001, when the Russian Soyuz-U booster blasted two Russian cosmonauts and a paying tourist, the American millionaire Dennis A. Tito, into orbit for a rendezvous with the International Space Station.

Electromagnetism holds great potential for sculptural levitation. Yet untapped, for example, is a property known as diamagnetism. Diamagnetic materials repel both the north and south poles of a magnet. All materials are weakly diamagnetic, but it is difficult to levitate ordinary objects. However, with a strong magnetic field and strongly diamagnetic materials (such as neodymium magnets and graphite blocks), it is possible to create stable regions for diamagnetic levitation.

Artists seeking to explore levitation beyond magnetism and electromagnetism can investigate advanced techniques presently only found in research laboratories. A high-temperature electrostatic levitator allows the control of heating and levitation independently and, unlike an electromagnetic levitator, does not require that the floating object be a conductor of electric charge. Acoustic levitators enable the suspension of liquids in a state of equilibrium through acoustic radiation force. Also, liquids can be suspended by a gas jet and stabilized by acoustic forces. Superconductor levitators enable objects to float above a magnet in fog of liquid nitrogen. With a laser levitator it is possible to trap gas bubbles in water and create a condition of stable levitation by applying optical radiation pressure of the light beam horizontally and vertically. Atom chips allow for the trapping and manipulation of clouds of atoms, which magnetically levitate above the chip's surface. Portable quantum labs promise to further expand the magnetic control of atom clouds levitating in free space. At last, as levitation touches biology, molecular magnetism is predicated on the application of ordinary but very strong magnetic forces over a regular object. The forces are directed upwards and take advantage of the very weak magnetic response of the object present in the field, enabling the levitation of objects usually not regarded as capable of levitation (such as plastics) and living organisms (plants, insects, small animals -- and conceivably humans, if the field could be made strong enough). The manipulation of the magnetic properties of nanosized objects is also a possibility, which could include macroscopic manifestation of the quantum behavior of these very small objects. Since levitation depends only on the dielectric properties of the various materials, if vacuum is replaced by certain media (such as fluids) quantum mechanical energy fluctuations would generate an attractive force between objects that are very close to each other. Thus, quantum levitation of objects in a fluid emerges as another practical direction for aesthetic research. Further developments in quantum levitation make it clear that astounding levels of control can be achiveved when superconducting materials are sandwiched between layers of gold and sapphire crystal and dipped into liquid nitrogen at minus 300 degrees Fahrenheit. In this case, when one manipulates levitating objects and changes their orientation, the objects retain their new position with absolute stability. Possibilities proliferate with pseudo-magnetic fields created with graphene stretched to form nanobubbles on a platinum substrate, or real laser "tractor beams," that can move very small particles or microbes. The latter is achieved through a hollow laser beam with a ‘dark core.’ One side of the particles (which are trapped in the 'dark core') remains in darkness while the other is illuminated by the laser, thus pushing the particles along the hollow laser conduit. These techniques offer a glimpse into the new artforms that might emerge when life in the international space station becomes more common, when colonization of the Moon goes from science fiction to science fact, and when the space program overcomes what, in the public opinion, is its most exciting challenge: landing human beings on Mars. The creation of new alloys and compounds in zero gravity, the continuous discovery of new optical and subatomic behaviors and the prospect of interplanetary colonization suggest that levitation and space exploration are more than a metaphor in art. They constitute a material and intellectual challenge that must be met.

NOTES

1 - Gravitropism is a Botany term. Roots have positive gravitropism because they grow in the same direction of gravitational forces (i.e. down). Stems on the other hand have negative gravitropism, as they grow against gravity (i.e. up).